In 1969 Peter Matthiessen set out with the expedition led by Peter Gimbel, whose aim was to find and film underwater for the first time the most dangerous of all sea creatures - the great white shark. Acting as the expedition's chronicler and spare hand (both on the surface and below), Matthiessen accompanied the crew from the Carribean to the whaling grounds off the Durban coast, to various islands in the Indian Ocean, to Ceylon, and finally to success off the bleak south coast of Australia.

Blue Meridian records the awesome experience of swimming in open water among hundreds of sharks, the beauties of strange seas and landscapes and the camaraderie, humour and tension of people who live in close proximity and risk their lives day by day.